Schizophrenia linked to increased autoimmune disease risk

Abstract

MedWire News: Patients with schizophrenia are more likely to develop autoimmune diseases than the general population, research suggests.

"Previous studies have reported that, compared with the general population, individuals with schizophrenia have a different prevalence of some autoimmune diseases and experience different immunological responses, which suggests that aberrant autoimmune responses may play a role in the aetiology of schizophrenia," explain Hui-Ju Tsai (National Health Research Institutes, Zhunan Town, Taiwan) and colleagues.

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However, they add that "the association between schizophrenia and autoimmune diseases has not yet been systematically investigated."

To address this, the researchers used data from Taiwan's National Health Insurance Research Database (NHIRD) for 2005 to identify 10,811 inpatients with schizophrenia and 108,110 age-matched controls without the mental health disorder.

They examined the prevalence of 34 autoimmune diseases among the participants, and used multiple logistic regression analyses to assess the risk for these disorders among schizophrenia patients.

The team found that the prevalence of 14 autoimmune diseases was increased in schizophrenia patients compared with controls.

By contrast, the risk for rheumatoid arthritis was significantly lower in schizophrenia patients compared with the control group, at an OR of 0.52.

Among the schizophrenia patients, Graves' disease was significantly associated only with male gender while rheumatoid arthritis was significantly associated only with female gender, after correction for multiple testing, the researchers note.

Tsai and team conclude in the British Journal of Psychiatry: "Our data indicated that a certain number of autoimmune diseases were significantly associated (either positively or negatively) with in-patients with schizophrenia."

They add: "The findings of comorbidity suggest that shared genetic components and shared aetiological pathways may occur in autoimmune diseases and schizophrenia.

"Further investigation of the interplay between genetic, immune and pathological mechanisms will provide a better understanding of the underlying aetiology of both schizophrenia and autoimmune diseases."